I believe we should

The right to a healthy and clean environment is important to our survival, it will limit what we can put in our rivers and our food and the air. It's needed to guarantee that we don't kill of our natural and non-renewable resources. It can also make new jobs by needing increased inspections

A healthy environment is only beneficial.

A healthy environment can aid a lot of things. It lessens the load on the healthcare system first of all, as things like pollution wouldn't be much less of a cause for any diseases. It increases the quality of life, and it's better to invest in green technology, because it doesn't have nearly as many drawbacks as fossil fuels.

How is that even enforceable?

Why? Why did you do this? My brain! It burns! I don't understand what in the world drove you to this but for the sake of all good and holy get it removed from your cerebellum immediately lest it spread throughout your whole being and turn you into a pile of stupid!

A clean environment is not a right.

A clean environment is a privilege, not a right. Conversely, the right to dirty up the environment is a privilege, not a right. I would love to see how that would be enforced in an industrial district, or anywhere with prevalent littering.In short, it would interfere with a lot of personal freedoms to simply slightly improve the air quality/soil quality/unfiltered water quality...It's not worth it.